In the last century, the development of communication networks has revolutionized the world, enabling real-time communication and transmission of information nearly anywhere in the world. More recently, the development of digital data networks has enabled the volume of information that the networks can carry to increase at an exponential rate. In order to reliably send data over the networks, standardized network communication models have been developed, such as the Open Systems Interconnection (OSI) model. The OSI model, and other network communication models, provides a conceptual framework for communication between computers. The OSI model itself does not provide any specific methods of communication. The specific methods for communication are defined by various communication protocols. In the context of data communication, a protocol is a formal set of rules, conventions and data structures that governs how computers and other network devices exchange information over a network. In other words, a protocol is a standard procedure and format that two data communication devices understand, accept and use to be able to communication with each other.
In modern protocol design, protocols are “layered” according to the OSI 7 layer model or a similar layered model. Layering is a design principle which divides the protocol design into a number of smaller levels or parts. Each part is configured to accomplish a particular sub-task and interact with the other levels or parts of the protocol only in a small number of well defined ways.
A wide variety of communication protocols exists. These protocols were defined by many different standards organizations throughout the world and by technology vendors over years of technological evolution and development. One of the most popular protocol suites is the Transmission Control Protocol/Internet Protocol (TCP/IP), which is the heart of many communications networks, including the Internet. The IP is responsible for exchanging information between routers so that the routers can select the proper path for network traffic, while the TCP is responsible for ensuring the data packets are transmitted across the network reliably and error free. Local Area Network (LAN) and Wide Area Network (WAN) protocols are also used in network communications. The LAN protocols can provide for the physical and data link layers of communications over various LAN media such as Ethernet wires and wireless radio waves. The WAN protocol suite often addresses the lowest three layers and defines communication over various wide-area media, such as fiber optic and copper cables.
Network communication has evolved over many years. Today's new technologies are based on the accumulation over years of technologies, some which are largely obsolete, but others of which continue to exist. Because of this, the protocols which define the network communication are highly inter-related. Many protocols rely on others for operation. For example, many routing protocols use other network protocols to exchange information between routers. To develop a complete technology that is useful in a network, very often a group of protocols is required in the same layer or across many different layers. Different protocols often describe different aspects of a single communication; taken together, these form a protocol suite. For example, Voice over IP (VoIP), a group of protocols developed by many vendors and standard organizations, encompasses a number of protocols across the 4 top layers in the OSI model.
Data transmitted across a network is typically directed or switched using switches that are dependent on the use of a specific type of protocol, such as TCIP/IP, User Datagram Protocol (UDP), Voice over Internet Protocol (VoIP), and the like. In order to communicate with a wide variety of different networks, a router may translate between the different protocols. This translation can be expensive in terms of the hardware and/or software complexity used to implement the router. Translation can also result in slow switching speeds, router congestion, and loss of protocol functionality.